This invention relates to 20-high cluster mills of 1-2-3-4 construction used for the cold rolling of metal strip. Mills of this general type are taught in U.S. Pat. Nos. 2,169,711; 2,187,250; 2,479,974; 2,776,586; and 4,289,013.
Existing methods of axial adjustment of the four first intermediate rolls operate by moving these rolls axially as pairs. One drive is used to adjust the upper two rolls together and a second drive is used to adjust the lower two rolls together. The upper two rolls have tapers at the operator side and the lower two rolls have tapers at the drive side, all four rolls being cylindrical in form, except for the taper at one side. For rolling, the start of the taper (i.e. intersection between tapered portion and cylindrical portion) is set close to the edge of the strip for best results. (i.e. to achieve the best strip flatness). As the width of the incoming strip changes from coil to coil, the tapered roll positions can be adjusted to suit, thus avoiding the necessity to change these rolls every time the strip width changes.
In U.S. Pat. No. 5,131,252, it was taught that improved strip profile control could be achieved by providing different profiles on all four first intermediate rolls and adjusting them axially individually, using four separate drives. Because of the restricted space in the area where these rolls are located, due to the fact that these rolls and their adjustment mechanisms are surrounded on all four sides by the six second intermediate rolls and the four drive spindles driving the four outer second intermediate rolls (known as the drive rolls), it is very difficult to fit four drives into the available space.
The present invention discloses a method for overcoming this difficulty, achieving four independent drives in the available space, with a rugged and easily maintainable construction.